Oscillating furnace



ZMQEZ Nov. 5, 1935. H. KLENCKE ET AL 050 ILLATING FURNACE Filed Nov. so, 1934 2 Sheets-Shet 1 Inventors; Hans K/en cke rMarlfred Sac/2S mm n@ m a: h: 1%: i Z Z A: fl mi a:

y Cl. (W m Afforfley Nov. 5, 1935. H. KLENCKE ET AL I 2,019,912

OSCILLATING FURNACE Filed Nov. 30, 1934 2 Sheets-Sheet 2 also, k mos Wig/7717717717711 I V lnventors: J H005 K/encke rMaflfr'ea' 506/25 Afforney Patented Nov. 5, 1935 UNITED STATES PATENT OFFICE 2,919,912 OSCILLATING FURNACE ration of New York Application November 30, 1934, Serial No. 755,278 In Germany November 30, 1933 16 Claims.

The present invention relates to oscillating furnaces, and more particularly, to an oscillating furnace having an elongated hearth provided with adjustable teeth.

It is an object of the invention to provide an oscillating furnace provided with oblique teeth which are capable of stirring and agitating a solid to bring it in intimate contact with a gas and of moving the stirred and agitated solid from a charging port to a discharging port.

It is another object of the invention to provide an oscillating furnace which has a plurality of retaining walls incorporated therein of such construction as to cause the movement of the solid alternately from one side of the furnace to the other.

A further object of the invention is to provide an oscillating furnace having a hearth which is elongated longitudinally and which is practically horizontal.

The invention also contemplates the provision of an oscillating furnace having overhead heat reflectors and overhead gas coolers and dust catchers incorporated therein.

It is likewise within the contemplation of the invention to provide an oscillating furnace having means for controlling the rate of movement of solids, under treatment, the degree of contact between the solids and air or gas, and the amount of air or gas and the preheat thereof.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional View of an oscillating furnace embodying the principles of the present invention;

Fig. 2 illustrates a sectional View taken on the line 2-2 of Fig. 1;

Figs. 3 and 4 are similar to Fig. 2, except somewhat fragmentary, showing the hearth in different angular positions;

Fig. 5 depicts a sectional view taken on the line 55 of Fig. 1;

Fig. 6 illustrates a longitudinal sectional view of a modified embodiment of the present invention; and

7 is a sectional view of Fig. 6 taken on the line l-1.

According to the principles of the present invention, the hearth level of an oscillating furnace is arranged practically horizontally or is inclined only to such an extent that no forward isplacement of the charge occurs. The horizontal arrangement is usually preferred, to the in.

clined arrangement due to the elimination of lateral pressure exerted by the furnace on the bearings or mountings at the lower end thereof. For effecting an oscillating movement of the furnace about its longitudinal axis, at least one circular 5 rail is provided around the upper and one around the lower end of the furnace together with supporting rollers in a manner similar to rotary tubular furnaces.

The improved furnace has a hearth having low 10 side walls and of a flat crowned roof. By the use of a low flat, crowned roof, the gas space or chamber is decreased over the charge and the heat is radiated to the surface of the charge. In case the heating is too great, for example, in the beginning of the treatment, it may be decreased by incorporating radiators or extensions in' the roof of the furnace for cooling purposes. Various means may also be provided in the roof for other purposes. Thus, a number of manholes or 2c doors may be provided for gaining access to the interior of the furnace or a number of nozzles, ports or openings with suitable connections for admitting air, reaction gases or steam, with burners for heating or with devices for introducing suitable materials for chemical reactions and the like.

On the hearth a plurality of teeth is mounted for stirring the material and for moving it forward and through the furnace. A refractory 3O and/or fire proof material such as, stainless steel, carb-orundum, fire brick or the like, is used for the teeth.

The position of the teeth is adjusted so as to thoroughly stir the material constituting the charge passing between them and to convey the material from one end of the furnace to the other when the furnaceis oscillated. In this manner, the charge is stirred intensively and the mate- 'rial is turned over continuously and is brought 40 into intimate contact with the air or gas in the furnace. In the first section of the furnace adjacent to the region of charging, teeth having wide surfaces are provided which will have the effect of giving a relatively strong movement to the ore, thus preventing, for example, the caking of the material due to an excessively brisk reaction. In the second section of the furnace, a plurality of transverse retaining walls is provided. These walls are preferably constructed so that the tops have an oblique slope. In other words, the transverse walls have their upper edge lower at one side than the other and the charge can only pass over the retaining walls during the oscillating movement of the furnace at the lower part of the oblique walls. The height of the retaining walls can be varied in accordance with the circumstances. Later during the reaction say in the second section of the furnace, it may be advisable to slow down the forward movement of the charge. The number of the stirring teeth is preferably increased in the second section of furnace towards the discharge or delivery end to increase the stirring action applied to the charge. At the same time, a suitable adjustment of teeth may be made to control the forward movement of the charge and to prevent excessive speeding up of the forward movement of the charge. The utilization of adjustable teeth makes it possible to adjust and control the movement of the charge to the reaction conditions.

In the drawings, a practical embodiment of the invention is shown for illustrative purposes. The reference character (I) designates a hearth of a furnace embodying the principles of the present invention. It will be observed that the hearth is approximately a plane and is provided with side walls (20) and with a flat, crowned roof (2). The elongated furnace is provided with a circular rail (3) at each end thereof which is supported on rollers (4). By means of gear (5) and drive (6),. the furnace can be oscillated about its longitudinal axis on the rails and rollers.

In the roof of the furnace, servicing doors or manholes (I) are incorporated. Under the doors and in the hearth, oblique and adjustable stirring teeth (8) and (9) are arranged preferably symmetrically to the center line of the furnace bottom. The teeth are preferably made of a fire proof or fire resistant material, such as, for example, stainless steel, carborundum, fire clay or brick, or the like. Adjustment of the teeth may be made by means of nuts and bolts (Ill) which extend through the hearth and bottom of the furnace. By employing this arrangement, worn out or broken teeth can easily be replaced through the servicing doors (1) As may be clearly seen from Fig. 5, the teeth (8) are arranged in the first section of the furnace in two symmetrical rows and are provided with relatively wide surfaces. These teeth are adjusted in an inclined position so that the material (ore, etc.) striking the surfaces of the stirring teeth during the oscillating movement of the furnace is pushed to one side and then to the other and, at the same time, is moved or conveyed towards the delivery end or discharging port of the furnace. In the second section of the furnace extending from an intermediate part thereof adjacent to the delivery end teeth (9) are provided. It will be noted that teeth (9) are smaller than teeth (8) but that a greater number is used. In the drawings, teeth (9) are shown about one half the size of teeth (8), but about double the number. It is preferred to make the teeth (9) wedge shape and to arrange them symmetrically with respect to the axes of the furnace. As may be seen from the drawings, teeth (9) are adjusted to an oblique position so that the material (ore, etc.) is pushed laterally from one side of the furnace to the other and, at the same time, is also moved or conveyed forward, towards and to the delivery end or discharging port of the furnace.

In the furnace, preferably the second section, a plurality of retaining walls H is built across the furnace to form a plurality of small chambers containing a group of teeth. The retaining walls are preferably anchored in the hearth and have their upper edges tapering alternately from one side to the other as may be seen from Figs. 2, 3, 4 and 7. When the furnace is oscillating the walls slow down the forward movement of the material in that part of furnace in which the walls are built. Due to the tapering construc- 5 tion the forward moving material (ore, etc.) can only move over the retaining walls at the lower side thereof. In this manner, all of the material is positively forced to move from one side of the furnace to the other. 10

A charging port (I2) is located at one end of the furnace and a discharging port (l3) at the opposite end as may be seen in Fig. l. Adjacent to charging port, a gas outlet (I4) is provided. At the discharge end of the furnace, say in the front wallthereof, an adjustable port (I5) is. positioned. Air, heating gas or the like may be introduced through port (IS).

The gas passing from the furnace to the gas outlet (M) can be cooled and the dust separated therefrom by incorporating radiators or members (IT) in the roof of the furnace. The heat radiator may be constructed by replacing portions of the roof of the furnace with heat conducting material, such as stainless steel, one side of which is exposed to the atmosphere in the furnace, While the other is exposed to the air. In order to increase the radiating surface of the heat radiators and to insure better contact between the radiators and the furnace gases, it is preferable to have the heat radiators project into the furnace. For instance, as shown in Figs.

1 and 6, radiators IT comprise metallic channels or other trough-like shapes projecting into the furnace space through suitable openings in the roof of the furnace. It is to be observed that by reducing the temperature of the furnace gases, the radiators also reduce the volume and the speed and consequently also the dust-carrying capacity of the gases, and that as a result thereof a substantial amount of dust is separated from the gases. The radiators are preferably made of a heat conducting material, such as stainless steel or the like. In practice it has been found that especially satisfactory results are obtained when the radiators are built in the furnace roof adjacent to the charging end. In the other sections of the furnace, it is desirable to build heat reflecting units H3 in the roof.

In the event that it is desired means may be incorporated in the furnace for cooling and at the same time utilizing the heat withdrawn from the furnace. Thus, tube i8 made of heat resisting material may be mounted on retaining walls and arranged longitudinally of and. ex- 5 tending through practically the entire length of the furnace. This tube projects through the roof of the furnace adjacent to the charging end thereof and is provided with an adjustable entry port. The exit or outlet port of the tube is 10- cated near the discharge end of the furnace. In Fig. 6, the discharge port is shown above the delivery port. Combustion air can be admitted to the furnace through tube !8. While the combustion air is flowing through the tube, it will become preheated. During its passage through the tube, the air will cool the furnace. When the preheated air is admitted into the furnace at the discharge end thereof, it is available as roasting or reaction air. Of course, other gases may be introduced in place of air through tube l8. For example, reaction gases may be introduced through the tube into the furnace.

From the foregoing description, the operation of the improved furnace is obvious to those skilled charging port l2.

in the art. Thus, material, such as ore like pyrite, is introduced into the furnace via the As the furnace oscillates back and forth, the ore is distributed thoroughly between the teeth projecting from the hearth. Satisfactory results have been obtained by controlling the charge to such an amount as to leave the tops or upper portion of the teeth completely or approximately free. As obtained hereinabove, the teeth push the ore from one side of the furnace tothe other and at the same time convey the ore forward during the oscillating motion of the furnace as may be clearly seen from Figs. 3 and l. From the drawings, it will be clear that during the oscillation the powdered ore will strike against the oblique surfaces of the teeth and the ore will be thoroughly stirred while, at the same time, being pushed forward a little. Due to this action, the air or other gas in the furnace over the charge has an opportunity to come into intimate contact over and over again with new particles of ore and to oxidize the same or react therewith.

When the ore reaches one of the retaining walls ll, it will be detained and will accumulate until the ore can pass over the lower part of the tapered upper edge of the wall. When the ore, has passed over the first retaining wall, it will be located in a compartment provided with teeth 9. Due to the large number of teeth 9, for instance, double the number of teeth 8, an increase stirring of the ore will occur and an increased contact between the air or reaction gases with the particles of the charge. Each of the retaining walls slows down the forward motion of the charge until it has accumulated high enough to pass over the lower end of the tapered wall. In this manner, the ore is continuously moved and stirred until it arrives at the discharge or delivery end of the furnace. reaches the delivery end under normal operating conditions, the roasting process, or the like, is finished.

It is to be observed that the present invention provides an apparatus in which the oscillating movement eliminates the complete overturning of the ore and eliminates the danger of the formation of a substantial amount of dust. At the same time, the large number of teeth makes it certain that the ore under treatment will be thoroughly stirred and will be brought in intimate contact with the ore or reaction gas.

In the event that you desire to speed up or slow down the forward movement of the material under treatment, the nutsand bolts attached to the teeth are loosened up and the position of the teeth is adjusted through servicing doors I bymeans of an appropriate tool. By adjusting the angle of the teeth, the speed of the forward movement of the ore may be controlled.

It is to be observed that the present furnace can be used not only for roasting purposes but also for carrying out reduction processes or chemical reactions between gases and solids. Thus, for example, the production of hydrogen sulfide from sulfides, the reduction of metallic oxides, and the like, may be carried out in the present furnace. In the event that it is desired, additional heating may be provided in the furnace, say through either end or through the roof of the furnace.

We claim:-

1. An oscillating furnace having an elongated hearth and provided with a plurality of teeth with oblique surfaces adapted to move solids un- When the ore der treatment from one side of the furnace to the other and forwardly through the furnace.

2. An oscillating furnace comprising an elongated hearth, a plurality of teeth mounted on said hearth at an angle to move solids under treatment from one side of the furnace to the other and forwardly thereof, and a retaining wall located at a region in the furnace where it is desired to slow down the movement of the solids under treatment.

3. An oscillating furnace comprising an elongated hearth, a plurality of teeth set at an angle to each other to move solids under treatment from one side of the furnace to another, and a second set of teeth located in a second section of the furnace, said second set of teeth being smaller than the first set of teeth but present in larger number to increase the stirring of the solids under treatment.

4. An oscillating furnace comprising an elongated hearth, a plurality of teeth having relatively wide faces arranged at an angle to each other in one section of the furnace adjacent to the delivery end, said teeth being arranged to move the solids under treatment from one side of the furnace to the other and to move the said solids forwardly through said furnace, and a second set of teeth mounted on the hearth in a secend section of the furnace extending from the region where the first section terminates to the delivery end of the furnace, said second set of teeth being smaller than the first set but larger in number and adapted to give increased stirring of the solids as the latter is pushed from one side of the furnace to the other and forwardly during oscillation of the furnace.

5. An oscillating furnace comprising an elongated hearth mounted for oscillating movement, a plurality of teeth arranged symmetrically with respect to the longitudinal axis of said hearth and set at an angle to move solids under. treat ment from one side of the furnace to the other and forwardly through the furnace, said teeth being mounted on the hearth from the charging end to an intermediate region of the furnace, and a plurality of teeth arranged symmetrically with respect to the longitudinal axis of the hearth and distributed from an intermediate region of the furnace to the discharge end thereof, said teeth being smaller than the first teeth but present in larger number and set at an angle to give increased stirring.

6. An oscillating furnace comprising an elongated hearth, a charging port at one end of said furnace, a discharging port at the other end of said furnace, a plurality of wide faced teeth in the section of the furnace extending from the charging port to an intermediate region thereof, said wide faced teeth being arranged symmetrically to the longitudinal axis of the hearth and set at an angle to each other to move solids under treatment from one side of the hearth to the other and forwardly through the furnace, a plurality of narrow faced teeth mounted on the hearth in the section of the furnace extending from the intermediate region thereof to the discharge port, said teeth being arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to push the solids from one side of the furnace to the other and forwardly thereof, and a plurality of retainingwalls located in said second section of the furnace.

7. An oscillating furnace comprising an elongated hearth, a charging port atone end of said furnace, a discharging port at the other end of said furnace, a plurality of wide faced teeth in the section of the furnace extending from the charging port to an intermediate region thereof, said wide faced teeth being arranged symmetrically to the longitudinal axis of the hearth and set at an angle to each other to move solids under treatment from one side of the hearth to the other and. forwardly through the furnace, a plurality of narrow faced teeth mounted on the hearth in the section of the furnace extending from the intermediate region thereof to the discharge port, said teeth being arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to push the solids from one side of the furnace to the other and forwardly thereof, and a plurality of retaining walls located in said second section of the furnace, said retaining walls being alternately sloped from one side of the furnace to the other.

8. An oscillating furnace comprising an elongated hearth, a charging port at one end of said furnace, a discharging port at the other end of the said furnace, a plurality of wide faced teeth in the section of the furnace extending from the charging port to an intermediate region thereof, said wide faced teeth being arranged symmetrically to the longitudinal axis of the hearth and set at an angle to each other to move solids under treatment from one side of the hearth to the other and forwardly through the furnace, a plurality of narrow faced teethmounted on the hearth in the section of the furnace extending from the intermediate region thereof 'to the discharge port, said teeth being arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to push the solids from one side of the furnace to the other and forwardly thereof, a plurality of retaining walls located in said second section of the furnace, and said teeth being movably mounted on said hearth.

9. An oscillating furnace comprising an elongated substantially horizontal hearth and a plurality of teeth of different form, number and angular adjustment associated with said hearth and adapted to move a charge forwardly on said hearth as the furnace oscillates.

10. An oscillating furnace comprising an elongated hearth, a plurality of teeth set at an angle to cause solids under treatment to move from one side of the furnace to the other and forwardly thereof, a plurality of retaining walls mounted on said hearth in spaced relation, and a heat resisting tube arranged on said retaining walls and extending throughout practically the entire length of the furnace from the charging end to the discharging end, said tube having an adjustable inlet near the charging end of the furnace and an outlet adjacent to the discharge end of the furnace.

11. An oscillating furnace comprising an elongated hearth, a plurality of teeth arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to each other to push the material from one side to the other and forwardly thereof, a low crown roof over said hearth, and a plurality of radiators in said roof to cool hot gases within the furnace .and to collect dust therefrom.

12. An oscillating furnace comprising an elongated hearth, a plurality of teeth arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to each other to push the material from one side to the other and forwardly thereof, a low crown roof over said hearth, and a plurality of heat reflecting units incorporated in the roof of said furnace to radiate the heat to solids under treatment on the hearth.

13. An oscillating furnace comprising a narrow elongated hearth, a plurality of rings surrounding said hearth and mounting the same for oscillation means for oscillating said hearth, low side walls extending upwardly from said hearth, a low crowned roof extending over said hearth, a charging port at one end of said furnace, a discharging port at the other end of said furnace, a gas outlet adjacent to the charging port, a plurality of wide faced teeth arranged symmetrically with respect to the longitudinal axis of the hearth in one section of said hearth extending from a region adjacent to the charging port to an intermediate region, a plurality of narrow faced teeth arranged symmetrically with respect to the longitudinal .axis of the hearth and set at an angle to push the material from one side of the furnace to the other and forwardly thereof, a plurality of retaining walls mounted on said hearth in spaced relation in the section extending from an intermediate region of the furnace to the discharging port, and means for introducing reacting gases into the interior of said furnace,

14. An oscillating furnace comprising a narrow elongated hearth, a plurality of rings surrounding said hearth .and mounting the same for oscillation, means for oscillating said hearth, low side walls extending upwardly from said hearth, a low crowned roof extending over said hearth, a charging port at one end of said furnace, a discharging port at the other end of said furnace, a gas outlet adjacent to the charging port, a plurality of wide faced teeth arranged symmetrically with respect to the longitudinal axis of the hearth in one section of said hearth extending from a region adjacent to the charging port to an intermediate region, a plurality of narrow faced teeth arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to push the material from one side of the furnace to the other and forwardly thereof, a plurality of retaining walls mounted on said hearth in spaced relation in the section extending from an intermediate region of the furnace to the discharging port, means for introducing reacting gases into the interior of said furnace, and a plurality of radiators incorporated in the roof of the furnace over said wide faced teeth and adapted to radiate heat and to collect the dust.

15. An oscillating furnace comprising a narrow elongated hearth, a plurality of rings surrounding said hearth and mounting the same for oscillation, means for oscillating said hearth, low side walls extending upwardly from said hearth, a low crowned roof extending over said hearth, a charging port at one end of said furnace, a discharging port at the other end of said furnace, a gas outlet adjacent to the charging port, a plurality of wide faced teeth arranged symmetrically with respect to the longitudinal axis of the hearth in one section of said hearth extending from a region adjacent to the charging port to an intermediate region, a plurality of narrow faced teeth arranged symmetrically with respect to the longitudinal axis of the hearth and set at an angle to push the material from one side of the furnace to the other and forwardly thereof, a plurality of retaining walls mounted on said hearth in spaced relation in the section extending from an intermediate region, of the furnace to the discharging port, means for introducing reacting gases into the interior of said furnace, and a plurality of heat reflecting units incorporated in the roof of the furnace over the narrow faced teeth and adapted to radiate heat to solids under treatment.

16. The method of treating solids which comprises charging said solids to an elongated hearth,

oscillating said hearth, causing said solids to come in contact with deflecting teeth mounted on said hearth and adapted to push the material from one side of said hearth to the other and forwardly thereof.

HANS KLENCKE. MANFRED SACHS. 

